Ryuunji Temple is a historic Soto Zen temple located in Iwamurada, Saku City, Nagano Prefecture. Its mountain name is Otazan, and its principal Buddhist image is the Eleven-Headed Kannon, a form of the bodhisattva of compassion.
Quietly situated amid the historic landscape of the Saku Basin, Ryuunji has played an important role in the area’s religious and cultural history for centuries. The temple is particularly notable for its connections with the powerful Oi clan and Takeda Shingen, as well as for the legends and historical remains preserved within its grounds.
The history of Ryuunji dates back to 1312, during the Kamakura period. The temple was founded by Oi Genkei, with the monk Jougaku Tenchu serving as its founding priest. It was originally established as a temple of the Rinzai school of Zen Buddhism.
After suffering decline as a result of warfare, the temple was revived during the Bunmei era (1469–1487) by Ten-ei Shotei, a monk of the Soto school. At this time, Ryuunji changed its Buddhist affiliation to Soto Zen, the tradition it follows today.
During the turbulent Sengoku period, the Takeda clan expanded its influence into Shinano Province. Takeda Shingen, then known as Takeda Harunobu, sought to strengthen the network of Soto Zen temples within his territory and developed Ryuunji as an important center for the sect in his domain.
Shingen invited the eminent monk Hokko Zenshuku from Echigo to Ryuunji. Shingen himself became the temple’s patron and supported its revival. Historical records place this development either during the Koji era (1555–1558) or after the Battle of Kawanakajima in 1561.
With Hokko’s arrival, Ryuunji rose in status and became a major religious center within the Takeda territories.
Hokko Zenshuku went on to serve as the leading authority over Soto Zen temples within the Takeda domain. In 1570, he contributed to the formulation of new regulations governing the sect.
In 1572, Ryuunji hosted a large Buddhist assembly known as a Hodo-e, reportedly attended by around 1,000 people. The temple’s prestige reached the imperial court as well, and an inscribed temple plaque was presented by Emperor Ogimachi.
One of the most intriguing stories surrounding Ryuunji concerns the death of Takeda Shingen in 1573, while he was leading his army westward.
Several locations are traditionally said to have been associated with Shingen’s cremation, and Ryuunji is one of them. In 1931, human remains and a tea kettle containing objects believed to have been associated with Shingen were discovered on the temple grounds. This led to speculation that part of Shingen’s remains had been secretly buried at Ryuunji.
The discovery became the subject of a legal dispute between the Japanese government and the temple, attracting considerable attention throughout Japan. Today, the story remains an important part of the temple’s historical lore, although the precise circumstances surrounding Shingen’s final resting place continue to be debated.
After the establishment of the Tokugawa shogunate, Ryuunji received official land privileges from the shogunate and maintained its status as an important temple.
A large number of historical documents preserved by the temple are collectively known as the Ryuunji Documents. Many of these records have been included in the historical collection Shinano Shiryō, providing valuable insight into the history of Saku and medieval Shinano.
Among the temple’s notable cultural assets are the grave monument of Zen Master Hokko, designated as a Nagano Prefecture Historic Site, and medieval documents from Ryuunji designated as cultural property by Saku City.
For visitors interested in Japanese history, these materials offer a glimpse into the religious, political, and social world of medieval Shinano.
To the northwest of the Main Hall is a well known as the Chanoyu Well. It is one of the seven historic wells of Iwamurada and is traditionally said to have provided water for tea served by members of the Oi clan.
To the southwest of the Main Hall is the Shingen Well. According to local tradition, Shingen prayed at the well and was able to obtain whatever he desired from its waters. The well is also said never to have run dry.
The history of Ryuunji can also be traced through the names of places surrounding the temple. The area known as Nio-mae is said to have once been the location of a Niomon gate, while the present Main Hall is traditionally believed to have stood farther south in an area called Ha-odaira.
Egeura refers to an area associated with Buddhist training and study. East of the temple is a place called Shojinba, where monks are said to have stayed during Shingen’s large Buddhist assemblies. Another area, Sugada, takes its name from the natural growth of sedge-like plants that once characterized the land.
A charming local legend concerns the names Iwao and Iwako. According to the story, Takeda Shingen intended to reward the temple with a place called Iwako. However, the temple mistakenly understood the name as Iwao, and the Iwao area consequently became part of the temple’s territory.
Whether or not the story reflects an actual historical misunderstanding, it has survived as one of the more lighthearted tales associated with Ryuunji.
Another story concerns an Oi lord of the Ogasawara family. When he was considering becoming a Buddhist monk while in Hoki Province, he reportedly dreamed of the guardian Nio statues at Ryuunji.
He came to worship the figures and, according to the legend, subsequently achieved success and advancement. The story reflects the temple’s long-standing connection with warrior families and local beliefs in divine protection.
Among Ryuunji’s colorful stories is that of a monk named Suitanbo. He was said to spend much of his time drawing rather than concentrating on his religious training. He also had a reputation for being fond of women, and was eventually expelled from the temple.
Even after leaving, however, legends tell of his being saved through the protection of Kannon. Other stories describe him being tricked by a mujina, a Japanese folklore creature often associated with mysterious transformations and supernatural mischief.
Suitanbo remains a memorable figure in local storytelling, adding a human and sometimes humorous dimension to the long history of Ryuunji.
Ryuunji Temple brings together more than seven centuries of religious history, samurai heritage, cultural treasures, and local folklore. Its connections with the Oi clan and Takeda Shingen make it particularly fascinating for travelers interested in Japan’s medieval history, while the temple grounds themselves offer a peaceful setting away from the bustle of major tourist destinations.
Ryuunji is approximately 15 minutes by car from either the Saku-Minami Interchange or Saku Interchange on the Chubu-Odan Expressway and Joshinetsu Expressway, respectively.
A visit can be combined with a walk through the historic area of Iwamurada-juku, allowing travelers to explore the landscape and heritage of Saku while discovering the stories preserved around this atmospheric Zen temple.